Tank trailers are used in industry to transport a wide variety of products. Each trailer includes a large tank that has a plurality of fill ports on a top wall. When the tank is to be filled or to be emptied, the operator has to climb onto the top wall and walk along the same to open one or more of the fill ports. Some of the tank trailers that are currently in operation have relatively flat top walls but frequently these walls are fairly narrow for the operator to wall along. Additionally, if the operator has to open more than one fill port or a particular fill port, it is necessary for him or her to step over the fill ports. Since these ports are raised relative to the top wall, they present a tripping hazard for the operator. Since the top walls can be situated several feet off the road surface, there is a substantial risk for the operator to fall off the tank and seriously injure himself or herself. Yet other tank trailers have curved top walls and the curvature thereof makes it even more likely that the operator will fall.
There is therefore a need in the art for an improved tank trailer that reduces the possibility of an operator falling off the top wall of the same.